Mirror object around a circle?
There's no need to include the mirror modifier in your setup, as the array modifier can do it all on its own. The important thing to note is that you want to use an 'Object Offset' and turn off 'Relative Offset'. You'll use the target object's rotation, which should be equal to 360/count. In this case, the empty was rotated 60 degrees, since the count is 6.



For some hands-on experimentation, have a look at the .blend